For example, as shown in FIG. 1, a conventional control system 100 for a servo motor is made under open loop control, as a glance at a motion controller, and makes compensation for a position and speed in a servo amplifier 120 (a speed loop control section 122 and a position loop control section 121) only, while utilizing a present command position, and a real position and a real speed that are obtained from a motor 130. That is, when target position-speed is given to the control system 100, a command pulse row generation section 112 by turns outputs position command values to the servo amplifier 120 as command pulse position command values, according to an output of a command speed waveform generation section 111. The servo amplifier 120 responds to the inputted position command values, and the position loop control section 121 and the speed loop control section 122 output control signals to the motor 130. That is, the motor 130 revolves according to the control signals and, according to the revolution, the real position and the real speed are fed back to the position loop control section 121 and the speed loop control section 122 in which a feedback control is performed.
In the above-mentioned prior art, in the event that the motor is operated at high speed, future command waveforms can not be grasped in the servo amplifier 120. For this reason, it is difficult to easily restrain vibration relative to an advancing direction or settling time. Moreover, the motor control is made under an accumulated error pulse (or a positional deviation pulse or an error pulse) mode, so that when synchronous control or the like is performed, it is difficult to cause the motor to be operated with an ideal track.
However, in the past, it is necessary to smoothly accelerate/decelerate a work or a unit supporting the work, so as not to apply mechanical shock to the work, and move the work. JP-A No. 03-36977 describes an acceleration/deceleration control method for a servo motor, in which in the servo motor that performs control of a position and speed while calculating a speed command value at real time, on the basis of command values of a target position, a target speed, and acceleration/deceleration time, the acceleration/deceleration time is divided into three regions including an acceleration increase region, an acceleration constant region, and an acceleration decrease region, and the acceleration/deceleration is performed while calculating the speed command value at real time in such a manner that the speed command value becomes constant in each region. Also, JP-A No. 2007-316702 describes a servo motor drive control system which receives a position command from a computer numerical control device repeatedly giving a periodical position command to a servo motor, receives a signal indicative of a position of a driven material from a position detector, demands a first correction data from means obtaining a first positional deviation between the position command and the position of the driven material, and controls the position of the driven material based on the first positional deviation and the first correction data. Moreover, JP-A No. 2009-187521 describes a position command preparing method and system, in which in the process of preparing a position command that accelerates according to a designation acceleration for each command cycle, until speed corresponding to a position command difference that is a difference between a this-time value and a last-time value of the position command reaches a designation speed, in the event that, if the speed corresponding to the position command difference is further accelerated, it can not deceleration-stop at a designation position at decelerated speed, the position command is prepared in such a manner to become speed corresponding to the position command difference, which deceleration-stops at a command position at decelerated speed and, if a jerk at a peak of a speed pattern formed from a relationship between the speed corresponding to the position command difference and a positioning time becomes larger than a jerk limit value predetermined by a program, the position command is prepared in such a manner that the jerk becomes equal to or less than the jerk limit value.